Estorch M, Serra-Grima R, Carrió I, Flotats A, Lizárraga A, Bernà L L, Prats T, Segura R
Department of Nuclear Medicine, Hospital de Sant Paul, Barcelona, Spain.
J Nucl Cardiol. 1997 Sep-Oct;4(5):396-402. doi: 10.1016/s1071-3581(97)90031-3.
A study was conducted to determine if prolonged exercise could provoke sympathetic neuronal alteration in an athlete's heart through assessment of myocardial distribution of 123I-metaiodobenzylguanidine (MIBG) in nine ultramarathon runners at baseline and after a 4-hour race.
After injection of 370 MBq of 123I-MIBG, the athletes ran for 4 hours, covering 45 +/- 8 km. Planar and single-photon emission computed tomography (SPECT) images of the thorax were acquired at the end of the race. Two weeks later, studies at baseline were performed. A heart:mediastinum ratio (HMR) was calculated to quantify MIBG uptake. Basal MIBG studies showed normal myocardial tracer uptake, on both planar and SPECT images, and the HMR was 1.84 +/- 0.16. After the 4-hour race, MIBG studies showed decreased myocardial uptake in all athletes, and the HMR was 1.70 +/- 0.18 (p < 0.005). A positive correlation between the percentage of decrease of HMR after the race and the distance covered was observed (r = .910, p < 0.001).
Myocardial MIBG activity is decreased by prolonged exercise in long-distance runners. The degree of reduction of myocardial MIBG activity is related to the distance covered. Prolonged exercise, as sustained sympathetic stimulus, may alter myocardial distribution of MIBG.
进行了一项研究，通过评估9名超级马拉松运动员在基线时和4小时比赛后的心肌中123I-间碘苄胍（MIBG）的分布情况，来确定长时间运动是否会引发运动员心脏交感神经元改变。
注射370MBq的123I-MIBG后，运动员跑了4小时，跑了45±8公里。在比赛结束时采集胸部的平面和单光子发射计算机断层扫描（SPECT）图像。两周后，进行基线研究。计算心脏：纵隔比值（HMR）以量化MIBG摄取。基础MIBG研究显示，在平面和SPECT图像上心肌示踪剂摄取均正常，HMR为1.84±0.16。4小时比赛后，MIBG研究显示所有运动员的心肌摄取均降低，HMR为1.70±0.18（p<0.005）。观察到比赛后HMR降低百分比与跑过的距离之间呈正相关（r = 0.910，p<0.001）。
长跑运动员长时间运动可使心肌MIBG活性降低。心肌MIBG活性降低的程度与跑过的距离有关。长时间运动作为持续的交感神经刺激，可能会改变MIBG的心肌分布。
